Deployable aerodynamic ring stabilizer

ABSTRACT

A foldable ring assembly for the aerodynamic stabilization of missiles. The ring assembly includes a plurality of arcuate segments pivotally interconnected by hinges between adjacent segments. Each segment is supported on the missile by a radial strut which is pivotally connected to both the missile and the segment. When in a missile launch tube, the struts are held in positions tangential to the missile and the interleaved segments partially overlap one another in close proximity to the missile case. Upon exit from the tube, torsion springs rotate the struts into radial positions causing the arcuate segments to unfold into a complete ring concentrically positioned around the missile.

United States Patent 11 1 Q [111 3,724,782

Gauzza et al. [4 1 Apr. 3, 1973 541 DEPLOYABLE AERODYNAMIC RING 3,260,205 7/1966 Dietrich ..244 3.23

STABILIZER V Primary Examiner-Benjamin Borchelt Assistant ExaminerJames M. Hanley Attorney-R. S. Sciascia et al.

[75] Inventors: Harry J. Gauzza, Silver Spring; Eu-

gene V. Horanoff, Clarksville, both of Md. 21029 [73] Assignee: The United States of America as 57 ABSTRACT represented by the Secretary of the Navy A foldable ring'assembly for the aerodynamic stabilization of missiles. The ring assembly includes a plu- Filed! J y 22, 1971 rality of arcuate segments. pivotally interconnected by [2 APPL No 165,240 hinges between adjacent segments. Each segment is supported on the missile by a radial strut which is I r pivotally connected to both the missile and the seg- [52] US. Cl. ..244/3.27, 102/3, 102/4 mam w in a missile launch tube, he struts are [51] Int. Cl. ..F42b 25/06, F42!) 25/02 held in positions tangential to the missile and h 581 Field 0! Search ..244 3.'27,3.2s,319,314, weaved segments partially overlap one another in 4 102/4 3 close proximity to the missile case. Upon exit from the tube, torsion springs rotate the struts into radial posi- [56] Rem-wees Cited V tions causing the arcuate segments to unfold into a UNITED STATES PATENTS CO HXPIICtC ring concentrically positioned around the mlSSl e. 3,188,957 6/1965 Petre 244/317 2,494,835 1/1950 Lax et al "102/4 7 Claims, 5 Drawing Figures 3 5 s6 52 +4 nf 5s o 1((\ m l I k i3 \1 f 62 04 64 9a w;1\\\\\\\\;zs\ 36 32 28 so as 34 68 3a as f 26 WENIEW 3 ms SHEET 2 OF 3 FIG. 2.

FIG. 4.

INVENTORS HARRY J. GAUZZA EUGENE l. HORA/VOFF FIG. 5.

PATENTEDAPR 3 I973 3. 724 782 sum 30F FIG. 3.

INVENTORS HARRY J. GAUZZA EUGENE V. HORANOFF DEPLOYABLE AERODYNAMIC RING STABILIZER BACKGROUND OF THE INVENTION Fins have been provided on aerial vehicles such as '10 missiles to stabilize the flight trajectory thereof and some missiles have been provided with foldable fins for the purposes of conserving storage space and minimizing handling problems. In some instances, the fin design necessitated that the fins be deployed manually to their operative positions prior to placement on a launching device; while in other instances, the fins were automatically deployed by springsor centrifugal force after the vehicle cleared the launching tube. Once in their operative position, the consequences of using fins, planar as well as curved, to stabilizea missile are the inherently high induced rolling moments which often cause anomalous flight. While it is generally advantageous to keep induced roll to a minimum for all rockets, it becomes essential to'do so for guided missiles because, if the roll rate of a guided missile is permitted to become too large, the seeker will lose its lock on the target and/or the control system response will be out of phase with the required maneuver, thereby causing the missile to turn away from the target. Since ringshaped stabilizers are known to induce lower rolling moments than fin designs, it is therefore desirable to provide guided missiles with ring stabilizers and further to. make such ring stabilizers of a collapsible design to allow tube storage; carry and launch which significantly improves operational effectiveness. Further, ring stabilizers have wide application and would be advantageous for unguided vehicles as well.

Collapsible stabilizing rings have existed in the past but in all known cases, the collapsible ring elements have been formed of flexible or. resilient materials, which was necessary to accommodate deflection of the ring elements when constrained in the collapsed position. Although the previously known collapsible stabilizing rings have been satisfactory in some applications, their use of flexible materials deleteriously effects the strength of the stabilizing structure otherwise attainable by rigid materials and necessarily precludes the use of lightweight rigid materials, such as aluminum, titanium, magnesium, and various alloys in the construction of the stabilizing rings. Therefore, with the continuing need for improved high accuracy missiles, there .has arisen a need for an improved missile stabilizing' device of, minimum weight, optimum strength capable of affording the necessary flight stabilization, and being substantially free of induced rolling moments. I

SUMMA Y OF THE INVENTION A further object of the invention is to provide a foldable ring stabilizer which is of minimum weight and optimum strength.

Still another object of the invention is to provide a foldable ring stabilizer which reliably and automatically opens from a folded position to its operative position immediately upon clearance of the missile from the launch tube.

These and other objects of the present invention are attained by providing a foldable stabilizer ring formed of a plurality of elongate arcuate segments which have a radius'of curvature greater than the radius of curvature of the aerial vehicle. The arcuate segments are pivotally interconnected with one another by a plurality of recessed hinge plates and each segment is supported upon the vehicle for pivotal movement about axes parallel to the axis of the vehicle by a radial strut. The pivotal interconnection of the arcuate segments by the hinge plates is such that, when the arcuate segments and radial struts are rotated, against the force of helical torsion springs acting upon the struts, into a position in close proximity to the periphery of the vehicle, the arcuate segments partially overlap one another. When the vehicle is launched, the helical torsion springs cause the radial struts to rotate into planes bisecting the axis of the vehicle, causing' the arcuate segments to unfold into an erected operative position in which they form a smooth cylindrical stabilizing ring which is cle.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a side elevation, partially cut away, of the stabilizing ring assembly mounted on the aft end of an aerial vehicle;

FIG. 2- is a transverse cross-sectional view taken along line 2-2 of FIG. 1 showing the stabilizing ring in its folded position;

FIG. 3 is 'a. transverse cross-sectional view taken along line 3 3 of FIG. 1 showing the stabilizing ring assembly in its operative deployed position;

FIG. 4 is a transverse cross-sectional view taken along line 4--4 of FIG. 1 showing the latching mechanism for locking the ring stabilizer in its erected position;and

FIG. 5 is a perspective view of one of the pivotal stops of the instant invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT launching tube. The cylindrical stabilizing ring 10 is formed of eight elongate arcuate segments 14 which spaced concentrically about the periphery of the vehiare curved about their transverse axis and have a radius of curvature which is greater than the radius of curvature of the missile. The forward or leading edge of the arcuate segments is aerodynamically tapered at and the longitudinal side edges of the segments are provided with oppositely disposed, elongate, rectangular cutout portions 16 and 18 so positioned that the cutout portions of adjacent arcuate segments 14 cooperate to define a larger rectangular cutout portion therebetween to receive a rectangular hinge plate 22. Rectangular hinge plates 22 are formed with a curvature along the transverse axis having substantially the same radius of curvature as the segments 14 so that when the ring stabilizer is in its deployed position shown in FIGS. 1 and 3, the outer periphery of the ring stabilizer forms a substantially smooth cylindrical surface. I

As seen in FIGS. 1 and 2, each'hinge plate 22 is pivotally connected to one of the arcuate segments 14 by hinge pins 24 positioned along one edge portion of the hinge plate in parallel alignment with the axis of the aerial vehicle, and is connected to the other adjacent arcuate segment 14 by hinge pins 26 which extend along the central axis of the hinge plate in parallel alignment with the axis of the aerial vehicle, thereby providing an over-center pivotal connection between adjacent pairs of arcuate segments.

Each of the elongate arcuate segments 14 is respectively supported upon the exterior of an aerial vehicle by means of a radial strut 28 which, as seen in FIG. 1, is preferably constructed in the form of a skeletal rectangle. The base 30 of the radial strut has a first tubular hub 32 formed on the forward end thereof and a second tubular hub 34 on the rearward end thereof for coaxial alignment with upstanding hub portions 36 and 38 formed in a forward hinge base 42 and a rearward hinge base 44, respectively. The hinge bases are adapted to be mounted upon the aft portion of an aerial vehicle by any conventional means such as welds, screws, bolts or the like. A first hinge pin 46 extends through the apertures formed in the upstanding support hub 36 and the tubular hub 32 on the forward end of the radial strut while a second hinge pin 48 extends through aligned apertures formed in support hub 38 and tubular hub 34 onthe aft end of the radial strut thereby pivotally supporting each radial strut on the vehicle for rotation about an axis parallel to the axis of the vehicle. Similarly, the outermost arm 29 of the radial strut is provided with a forward tubular hub 52 and a rearward tubular hub 54 in coaxial alignment with inwardly extending tubular hubs 56 and 58 formed on the inner surface of the arcuate segments 14 along the central axis thereof. Hinge pins 62 and 64 extend, respectively, into coaxially aligned tubular hubs 56 and 52 and into tubular hubs 54 and 58.

22 thereby causing the arcuate segments to assume a partially overlapping position relative to one another when in the retracted position shown in FIG. 2.

To cause the automatic opening of the ring stabilizer from the retracted position shown in FIG. 2 to the deployed position shown in FIG. 3 immediately upon clearance from the launching tube, each of the radial struts 28 is resiliently biased for pivotal movement in a counterclockwise direction as seen in FIGS. 2 and 3. The resilient biasing means, more clearly shown in FIG. 1, includes a helical torsion spring 68 wrapped around a portion of the hinge pin 48 and having one terminal end portion 70 in abutting contact with the tubular hub 38 of hinge base 44 and having the other terminal end portion 72 thereof wrapped around the radial strut 28. While the aerial vehicle is in its launching tube, the ring stabilizer is constrained in the retracted position shown in FIG. 2 against the force of torsion springs 68 but as soon as the vehicle is launched and the ring stabilizer assembly clears the launching tube, the springs 68 immediately rotate the radial struts in a counterclockwise direction to expand the arcuate segments into the cylindrical ring configuration shown in FIG. 3. To secure the ring assembly in its deployed position, the counterclockwise rotation of the radial struts is arrested by a strut latching mechanism 74 shown generally at 74 in FIG. 1 and which is more clearly illustrated in FIG. 4.

' The strut latching mechanism 74 includes an elongate By this construction, each of the radial struts is pivotally supported for movement between the positions shown in'FIGS. 2 and 3. Since the pivotal connection of the struts to the arcuate segments is along the central axis of the segments, pivotal movement of the radial struts, in the direction of arrow 66 in FIG. 2, into positions substantially tangential to vehicle causes the segments to retract to positions in close proximity to the periphery of the vehicle casing. This movement also produces over-center pivotal action of the hinge plates rectangular channel member 76 having an elongate latching block 78 telescopically received therein and being resiliently biased outwardly by a spring 82, which may be either a helical spring, a resilient undulating flat band, or any other suitable spring means. The latch block 78 has an outwardly opening slot or channel 84 for receiving the base 30 of the radial strut when the strut occupies a plane which bisects the axis of the aerial vehicle. Slot 84 is defined by a pair of parallel upstanding ribs 86 and 88 with the uppermost surface of rib 86 being beveled inwardly at 92 toward the slot to facilitate entry of the strut base 30 as it rotates in a counterclockwise direction. When the ring stabilizer is in its retracted position, the side of base member 30 engages the top portion of rib 84 urging the latching block 78 downwardly against the spring into the channel member 76. As the ring stabilizer opens towards its erected position shown in FIGS. 3 and 4 and the bottom edge of the base 30 of the radial strut comes into alignment with the slot 84, spring 82 forces the latching block outwardly into capturing engagement with the bottom portion of the base 30. In this position the upstanding ribs 86 and 88 engage the flat sides of the base member 30 to prevent further rotation of the radial strut in either direction. As also shown in FIG. 4, an elongate bar 94 is secured by any suitable means to the interior surface of the arcuate segments 14 in proximity to the pivotalconnect ion of the radial strut 28 to the arcuate segment so that the outermost arm 29 on the radial strut abuts against the elongate bar stops 94 when the radial strut assumes the erected position.

To further assist in the locking of the ring stabilizer in the erected position, the ring stabilizer is provided with a plurality of pivotal stops shown generally in FIG. I by numeral 96 and more clearly shown in FIG. 5. The pivotal stops include a tubular hub portion 98, a longitudinally extending arm portion 100, and a pair of mutually perpendicular flat surfaces 102 and 104. As

seen in H6. 1, the tubular hub portion 98 of the pivotal stop is pivotally supported on hinge pin 64 between the tubular hub portions 54 and 58 formed on the radial strut and the arcuate segment, respectively. When the ring stabilizer is in the erected position, the surface 104 on the arm 100 of the pivotal stop is in abutting engagement with an arm of the radial strut 28, and the mutually perpendicular flat surface 102 on top of the pivotal stop conformingly engages the inner surface of the arcuate segment 14. Therefore, the abutting contact of the mutually perpendicular surfaces 102 and 104 of the pivotal stop with the arcuate segment and the radial strut, respectively, prevents the ring stabilizer from moving beyond its erected position as it opens from its folded position to the erected position and add rigidity to the ring stabilizer assembly when in its erected position. It is further noted that the back surface 106 of the pivotal stops is beveled so as'to prevent interference between the parts when the stabilizer ring is folded into its retracted position.

From. the foregoing description, it will be appreciated that the stabilizer ring of the present invention is operative to automatically open from a retracted position to a deployed position immediately upon clearance from a launching tube. In the retracted position, the outermost extremities of the retracted ring assembly do not protrude beyond the dimensions of the bore riders 13 and therefore do not occupy any additional space within the launching tube. Moreover, the ring stabilizer of this invention is provided with articulated joints which permit movement of the ring assembly between its retracted position and its open or deployed position without bending or otherwise deforming the arcuate segments. By this construction, the ring stabilizer of this invention maybe constructed of rigid light-weight materials to achieve optimum strength and rigidity while adding only a minimal amount of weight to the aerial vehicle. Further, the strut latching mechanism, elongate stop bars, and pivotal stops cooperate with the radial struts to rigidly lock the ring stabilizer in its erected or deployed position thereby adding additional strength and rigidity to the deployed ring stabilizer. The ring stabilizer of this invention exhibits low drag, equal stability in all planes, minimal induced roll, and approximately double the aerodynamic restoring moments of a cruciform planar fin of equal total span and chord.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. Although the preferred'embodiment of this invention has been illustrated as having eight arcuate segments defining the ring stabilizer, it is understood that greater or lesser number of arcuate segments could be similarly employed. Although the preferred embodiment has been described as having a helical torsion spring operatively associatedwith each of the radial struts and as having a latch mechanism operatively as sociated with each of the radial struts, it is understood that the ring stabilizer could be designed with a lesser number of these components without seriously effecting its operation. It is therefore to be understood, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A foldable ring stabilizer for an aerial vehicle comprising:

a plurality of rigid arcuate segments having a radius of curvature greater than the radius of curvature of the vehicle,

pivotal interconnection means for connecting adjacent ones of said segments for relative pivotal I rotation about axes parallel to the axis of the vehicle, and

a plurality of radial support struts each pivotally connected to, a respective one of said segments for relative rotation therebetween about axes parallel to the axis of the vehicle, and being adapted to be pivotally connected to the external periphery of the vehicle for rotation about axes parallel to the I axis of the vehicle,

. whereby said segments are adapted to be moved from a folded position, in which the segments partially overlap one another in close proximity to the periphery of the vehicle, to an erected position in which the segments form a cylindrical ring concentrically spaced around the periphery of the vehicle.

2. The apparatus of claim 1 wherein:

said pivotal interconnection means includes a plurality of rectangular hinge plates each positioned within complementary shaped cutout portions in interfacing edges of adjacent segments,

- each of said hinge plates being pivotally attached along one longitudinal edge portion thereof to one of said adjacent segments and being pivotally attached along its central axis to the other adjacent segment.

3. The apparatus of claim 2 further comprising means for resiliently biasing said struts for movement from a folded position to an erected position.

' 4. The apparatus of claim 3 further comprising locking means operably associated with said struts for engaging and locking said struts in the erected position.

5. The apparatus of claim 4 wherein:

said locking means includes a latching block slidably received within a support member adapted to be mounted upon the vehicle below a base portion of the radial strut, I

means for resiliently biasing said latching block outwardly from said support member, I

said latching block having an outwardly opening channel formed therein to lockingly receive a base 7. Theapparatus of claim 5 wherein said locking means further comprises:

at least one pivotal stop member rotatably supported at the pivotal connection of the radial strut to the arcuate segment, said pivotal stop having mutually perpendicular surfaces formed thereon to engage said radial strut and arcuate segment to prevent movement thereof beyond its erected position.

# i I t 

1. A foldable ring stabilizer for an aerial vehicle comprising: a plurality of rigid arcuate segments having a radius of curvature greater than the radius of curvature of the vehicle, pivotal interconnection means for connecting adjacent ones of said segments for relative pivotal rotation about axes parallel to the axis of the vehicle, and a plurality of radial support struts each pivotally connected to a respective one of said segments for relative rotation therebetween about axes parallel to the axis of the vehicle, and being adapted to be pivotally connected to the external periphery of the vehicle for rotation about axes parallel to the axis of the vehicle, whereby said segments are adapted to be moved from a folded position, in which the segments partially overlap one another in close proximity to the periphery of the vehicle, to an erected position in which the segments form a cylindrical ring concentrically spaced around the periphery of the vehicle.
 2. The apparatus of claim 1 wherein: said pivotal interconnection means includes a plurality of rectangular hinge plates each positioned within complementary shaped cutout portions in interfacing edges of adjacent segments, each of said hinge plates being pivotally attached along one longitudinal edge portion thereof to one of said adjacent segments and being pivotally attached along its central axis to the other adjacent segment.
 3. The apparatus of claim 2 further comprising means for resiliently biasing said struts for movement from a folded position to an erected position.
 4. The apparatus of claim 3 further comprising locking means operably associated with said struts for engaging and locking said struts in the erected position.
 5. The apparatus of claim 4 wherein: said locking means includes a latching block slidably received within a support member adapted to be mOunted upon the vehicle below a base portion of the radial strut, means for resiliently biasing said latching block outwardly from said support member, said latching block having an outwardly opening channel formed therein to lockingly receive a base portion of the radial strut when the strut has been moved to its erected position.
 6. The apparatus of claim 5 wherein said locking means further comprises: at least one elongate bar mounted upon the inner surface of the arcuate segment in proximity to the pivotal connection of the radial strut to the segment for preventing rotational movement of the strut beyond its erected position.
 7. The apparatus of claim 5 wherein said locking means further comprises: at least one pivotal stop member rotatably supported at the pivotal connection of the radial strut to the arcuate segment, said pivotal stop having mutually perpendicular surfaces formed thereon to engage said radial strut and arcuate segment to prevent movement thereof beyond its erected position. 